守护进程

关于守护进程需要强调两点：

其一：守护进程会在主进程代码执行结束后就终止

其二：守护进程内无法再开启子进程,否则抛出异常：AssertionError: daemonic processes are not allowed to have children

from multiprocessing import Process
import time

def task(name):
    print('%s is running' %name)
    time.sleep(2)
    p=Process(target=time.sleep,args=(3,))
    p.start()


if __name__ == '__main__':
    p=Process(target=task,args=('子进程1',))
    p.daemon=True
    p.start()

    p.join()
    print('主')

练习题

from multiprocessing import Process

import time
def foo():
    print(123)
    time.sleep(1)
    print("end123")

def bar():
    print(456)
    time.sleep(3)
    print("end456")

if __name__ == '__main__':
    p1=Process(target=foo)
    p2=Process(target=bar)

    p1.daemon=True
    p1.start()
    p2.start()
    print("main-------")